Anesthesia machines used in hospitals usually need to provide the following three different gas outlets, namely, auxiliary gas outlet, auxiliary common gas outlet, and breathing circuit gas outlet. At any moment, only one of the three outlets is in an available state. Hence, a doctor, at any moment, needs to clearly know which gas outlet is in an available state, to ensure that gases can be provided to a patient in the manner conceived by the doctor.
The existing anesthesia machines usually adopt the structure as shown by FIG. 1 to allocate oxygen, air, and N2O as required by the doctor. That is, oxygen, air and N2O from high pressure equipment 1 are mixed via mechanic or electronic flow control valves 2, 3, 4 respectively. The mixed gases are output to gas outlets as required by the doctor via manually or electrically actuated selector valves 5 and 6 controlled by the doctor. US Patent Application Publication No. 2010/0175695 A1 also discloses an anesthesia machine structure which is improved on the basis of the structure as shown in FIG. 1.
However, the prior art including US Patent Application Publication No. 2010/0175695, does not provide a technical solution capable of timely signaling a user of an anesthesia machine what gases are mixed together currently, and which gas outlet is available.